In general, fabrication of semiconductor devices such as LEDs or LSIs involve electrically-connecting semiconductor elements with a wiring lead which is composed of a metal plate. The semiconductor element and the wiring lead, with electrical connection established therebetween, are packaged in a resin-covered state.
More specifically, the semiconductor element and the wiring lead are injection-molded using resin. The injection molding is performed by inserting the wiring lead with the semiconductor element adhered thereon between dies, and by injecting thermosetting resin into a cavity formed between the dies (for example, refer to Patent Literature 1).
FIG. 7 shows a resin adhesion step where a wiring lead 102 and a semiconductor element 106 are coated with resin. FIG. 7A shows the wiring lead 102. FIG. 7B shows a state in which the semiconductor element 106 is adhered onto and electrically connected to the wiring lead 102. More specifically, the semiconductor element 106 is adhered onto the wiring lead 102 by die bonding, and electrically connected to the wiring lead 102 by wire bonding using a wire 108.
FIG. 7C shows a state in which a semiconductor intermediate product as depicted in FIG. 7B including the wiring lead 102 is attached to a die for resin coating. The semiconductor intermediate product is resin molded as a resin body 160 by using dies 100 and 110. More specifically, the molding of the resin body 160 is performed such that resin is injected from a resin injection gate 120 and air is released from an air vent 140.
FIG. 7D shows the semiconductor intermediate product yielded by molding the resin body 160.
As it could be seen, the center portion of the wiring lead 102 is covered by the resin body 160. However, resin burrs are formed on peripheral regions 102a of the wiring lead 102 by resin leaking out via gaps formed between the upper and lower dies 100 and 110.
The formation of resin burrs inhibits the electrical connection between the semiconductor element and the wiring lead, and also has negative influences on the solderability and appearance of the wiring lead. Hence, methods for removing resin burrs have been introduced, including such examples as a method of spraying liquids at a high pressure to regions where resin burrs have been formed and a method of roughening a predetermined region of a surface of a die to a specific surface roughness and thereby forming an irregularity on the burr which facilitates removal thereof from the die (for example, refer to Patent Literature 3).
FIGS. 22A through 22D show manufacturing steps for a resin-sealed QFP (Quad Flat Package) semiconductor device.
In the manufacturing steps depicted in FIGS. 22A through 22D, first, a semiconductor chip 94 is mounted onto a die-pad 93b of a wiring lead 93 (including die-pads 93a and 93b), and the semiconductor chip 94 and the die-pads 93a and 93b are connected via a wire 95. Thereafter, the wiring lead 93 is disposed on a fixed die 92 (FIG. 22A).
Next, a movable die 91 is pressed on the fixed die 92 such that the dies 91 and 92 are closed together to form a cavity 97 therebetween. A thermosetting resin is injected into the cavity 97 via a gate 96 provided in the movable die 91, thereby resin-sealing the semiconductor chip 94. (FIG. 22B).
After hardening the thermosetting resin, the dies 91 and 92 are opened, and an ejector pin (undepicted) is used to press out a resin cast 9z. Subsequently, outer leads 931a of the resin cast 9z are bent, thereby yielding a semiconductor device 9 (FIG. 22C).
In implementation of the semiconductor device 9, the outer leads 931a are connected to a substrate 99 via solder 90 (FIG. 22D).
The above are exemplary manufacturing steps for a QFP semiconductor device. There are other types of semiconductor devices, such as a light emitting diode (LED) device. An LED device is manufactured by, for example, forming a substrate in the interior of a mortar-shaped reflector such that a portion of a wiring lead is exposed, and mounting and connecting an light emitting diode element on the wiring lead in the reflector, and thereafter filling the interior of the reflector with a transparent sealing resin.
As for material to be used as sealing resin, silicone resin with a higher light transmittance is currently becoming more widely used in place of epoxy resin,
Furthermore, film carrier tape, examples of which are TAB (Tape Automated Bonding) tape, T-BGA (Tape Ball Grid Array) tape, and ASIC (Application Specific Integrated Circuit) tape, and which is used in the implementation of electrical parts of the IC, LSI, etc., has a structure in which an insulating film composed of a polyimide etc., a wiring pattern layer composed of Cu, and a solder resist layer are laminated in the stated order. Here, resin materials are used as the insulating film and the solder resist layer.